User–defined Load Balancing

Enterprise Server enables the administrator to define a custom policy for
distributing HTTP requests. A custom policy defines the load balancing algorithm
that the load balancer plug-in must use. In other words, the Administrator
can define which instance will handle an HTTP request. To use this feature,
the administrator needs to develop a shared library, which must implement
an interface called loadbalancer.h. The shared library
can, for example, be used to evaluate the headers of incoming requests provided
to it and in accordance to some criteria, select the instance that can serve
the request. This shared library would be loaded by the load balancer.

The interface loadbalancer.h is available under webserver_install_dir/plugins/lib/install. Enterprise Server also bundles
a shared library called roundrobin.c, that the administrator
can use as a template to build the shared library.